


Has Science Gone Too Far?

by TwigstheShifter



Category: Undertale (Video Game)
Genre: Ecto-Penis (Undertale), Other, joke, oh lord there's a fire
Language: English
Status: Completed
Published: 2016-07-08
Updated: 2016-07-08
Packaged: 2018-07-22 09:51:34
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 928
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7431101
Author URL: https://archiveofourown.org/users/TwigstheShifter/pseuds/TwigstheShifter
Summary: <blockquote class="userstuff">
              <p>Ok this is a joke fic. Please don't take any of this seriously, I just wrote it to make myself laugh.</p>
<p>Reader challenges Sans to make himself larger after a disappointing night in the bedroom.</p>
            </blockquote>





	Has Science Gone Too Far?

**Author's Note:**

  * For [Ajpuppy](https://archiveofourown.org/users/Ajpuppy/gifts).



> Thank @Ajpuppy for this, she inspired me with a UF!SansxReader fic during Buttercupsticks' picarto stream.

In the Underground, there is a strange rule, many who live outside Snowdin wonder how it came to to be. It has never been written in any history book, and honestly you think Asgore wants to forget about the whole thing. But you know how it happened, and it makes for a great story during the holidays. In fact, you celebrate the law's anniversary every year with a retelling at the library.

You had been seeing Sans for a couple months now, the sex had been interesting especially with the capabilities of a magic dick. He could change shape, but Sans kept the girth a constant size, you considered it was because the skeleton was afraid of hurting you. One night, you were finally done with the monotony. 

"Why don't you ever make it bigger?" you huff, finished but not satisfied.

"i dunno, i guess i'm too lazy" he shrugs, putting on his glasses to read.

You had a devious thought, one that might be able to get you what you wanted so desperately. Sans was humming while he read.

"I bet you can't get any bigger." you mutter.

"i can too, it's just a lot of work and it's exhausting." he defended.

"Prove it." you tease.

"ok gimme a minute, then you'll see." 

Sans put his glasses and book on the nightstand, then got up. He closed his eyes and started rubbing his pubis, soon the telltale glow shed a soft light on everything. You turn on the lamp to see it better, and you're impressed. It's about the size and shape of a water bottle, and you were thirsty. You scoot towards Sans, getting wetter and wetter. He raises an eyebrow, and gets closer as well. He kisses you tenderly, and you put your hands on his shoulders. You feel something soft poking at your stomach.

It's Sans erection, and it was still getting thicker, it was nearly as big as a jar.

"Oh my god, Sans."

Sans was sweating, but still keeping his cool. He pushes you onto the bed.

"it's fine, you said you liked them big. no need to be a...dick about it."

Your eyes widen as you can actually see his penis getting bigger. It was almost as big as a liter bottle of soda now, but you weren't thirsty, you were concerned.

"Ok you proved your point, now STOP." you shout.

"i can't." he falters.

Ok this was getting scary and excessive, his member was almost the size of a pillow.

"OH MY GOD IT'S GOING TOO FAST." you scream.

"WHAT'S WITH ALL THE YELLING?" Papyrus slams open the door.

His eyes widen as he realizes what you two were doing. He tries to look away but Sans' massive cock catches his eye. Papyrus has a thousand mile stare before fainting. This was getting to be too much.

"bro!" Sans calls, falling off the bed. His dick manages to keep him upright though, like a bull elephant.

You're freaking out because Sans' dick was still growing in size, and now Papyrus was passed out in the middle of the bedroom. You smell smoke, and suddenly a high pitch screech comes from the kitchen. Oh no, Papyrus had been cooking. You run downstairs and there's a fire in the kitchen. You can't deal with this right now, so you call Grillby since you figure a fire man will know how to deal with flames. He's there in a flash, and as soon as you let him in you go back up to check on the brothers.

Papyrus was still out cold, and Sans' dick was almost as big as the bed. His feet weren't even touching the ground, only penis. Grillby knocks on the door and peeks inside.

"Hey, uh, we need to leave." He manages to get out before he too passes out at the sight of Sans' thing.

You look out and sure enough, the house was more on fire now. GG Grillby, GG.

"Sans, can you move?" 

"with my legs?" he flails them uselessly, "nope."

Great googly moogly it's all gone to shit.

The fire dogpartment knocked down the door and started working on putting out the flames.

"Is there anyone upstairs?" one barked.

"Don't come up here!" You scream, but it's too late, the dog too passes out.

"ok i think i should leave." Sans says.

He teleports out, because his dick was too big to go out anywhere else. It was nearly filling the room. Once he left, everything felt a little calmer, and you manage to drag Papyrus, Grillby, and the dog out to safety. The fire was almost out by this point, and Gerson was treating everyone for smoke inhalation. Your mind, once everyone is getting cared for, goes back to Sans. You wonder where he went. You don't wonder long because at the top of the tree line you can see his skull peeking out.

Someone screams and points, causing everyone to scatter.

Assgore is here now, apparently news travels fast and this was the most interesting thing going on right now. He took one look at Sans, then turned to you.

"You asked for him to make his dick bigger, didn't you?" Asgore scolded.

He sighed and walked into the forest where Sans was, disappearing from sight. You hear a yelp, and Asgore is back in a flash, with a normal sized Sans trailing him.

"hey, thanks a-"

"Don't mention it, ever."

And that's the story of how it's illegal to have your genitals bigger than 5% of your body mass index.


End file.
